4th and 5th gear slipping

on my 02 yz426 in 4th and also in 5th gear the engine slips and it is really making me mad. i tried to isolate it to the clutch the sprocket and the rear wheel. i thought those were slipping, but they are fine. it did feel like the clutch so i changed it but it is still doing it. please help me..

I have a 98 400. The only thing that it could be is in the clutch. 1) is the clutch adjusted properly? 2) did you assemble the new clutch properly? I know that on the 400, there is one clutch plate in the stack that has a slightly larger inside diameter. This disc goes against the pressure plate. That would be the first plate you see after you remove the bolts and clutch cover (or pressure plate). you might want to check your manual to see it this holds true for your model. The higher the gear, the higher the torque to the clutch. With this plate installed inproperly, the disc won't sit flush on the pressure allowing the clutch to slip.

thank you, i will try that, but before i put on the new clutch it was doing that same problem when the old clutch was installed.

thank you, i will try that, but before i put on the new clutch it was doing that same problem when the old clutch was installed.

Did you replace the springs?

i replaced the springs with the new clutch. its weird that it only does it in 4th and 5th gear. i changed the chain guide slide and all the other parts that i thought could be causing that. maybe the 4th and 5th gears are gone, because i found a concerning amount of metal shavings in the oil filter. i just don't want to take it in to the shop and pay 100 bucks for someone to find out that it is a dumb problem, but i can't ride it like that. :ride:

Hi fellow 426 rider....

I am sad to say that it is most likely a gearbox problem!

Does it seem like it is "surging" . I had this problem with 4th gear. It is most noticable on hard surfaces. If this is the case it will almost 100% be worn dogs.

Unfortunately you will have to split the cases... replace worn gears and you may as well replace all shift forks while you are there!

I did this about 6 months ago. Dont skip the little things.... get all new washers and clips in the gearbox too.


no i would not say its surging just like it goes into neutral for a second when i am on the throttle in 4th and in 5th gear. i can feel the clutch handle move a little when it does it. :ride:

how much do you think it costs to do that by a professional, i don't have the time myself to do that. :ride:

Prepare to spend a little money for the fix. I had the same problem with my 00 426. Gears and shifting forks had to be replaced. While they have it split open, you might as well get an overhaul done too.

I had the same problem on my 426. It felt like the bike was surging at high speed in 4th and 5th, I thought it was the clutch also. But it turned out the bike was jumping in and out of gear, the dogs on the gears get rounded off and slip.

It's going to be expensive, I took the opportunity to have the head ported and have a high compression piston installed at the same time as having the transmission fixed. The engine builder basically replaced the entire transmission, total cost $1,700!

It cost me about $800AU in Parts.....

The parts are heaps cheap there in the US.... we Aussies get ripped off!

If you dont want to do it yourself..... find a mate or someone to do it for you..... anyone with a bit of mechanical knowledge can tackle it with the manual! A shop will charge you heaps!


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